Oldest Dinosaur?

SCIENCE AND MEDICINE SCOPE

November 19, 1989

Working from fossils discovered in the foothills of the Andes Mountains, scientists have reconstructed what they believe to be the oldest known dinosaur, the 230-million-year-old Herrerasaurus. Scraps of Herrerasaurus fossils were first discovered in Argentina 30 years ago, but only this year was a group of paleontologists able to gather a complete enough skeleton to draw an accurate picture of the animal. According to University of Chicago researcher Paul Sereno, who led the team, the Herrerasaurus measured between six and eight feet from head to tail, weighed about 300 pounds, and had a strange double hinged jaw that allowed it to hold struggling prey. The discovery brings scientists closer than ever to the first dinosaur, a still unknown creature that is believed to lived some 10 million to 15 million years before the Herrerasaurus, bridging the evolutionary gap between it and the crocodile-like reptiles that served as the ancestors of all dinosaurs.